Background: Obstructive adenotonsillar enlargement is known to cause failure to thrive in children. The effect of adenotonsillectomy is not well documented on the growth of affected children. The study was carried out to investigate the effect of adenotonsillectomy on growth of children with obstructive adenotonsillar enlargement. It was a quasi-experimental study consisting of 62 children (≤ 12 years) with obstructive adenotonsillar enlargement and 62 healthy controls. Variables measured at baseline, sixth week and 13th week post adenotonsillectomy, were weight, height, mid-upper arm circumference, and triceps skinfold thickness. The percent of weight-forage and height-forage were, respectively, calculated by dividing the child's weight and height by the median expected weight and height (i.e., the 50th percentile) based on the child's chronological age. The obtained weight-forage and height-forage values were used to determine the presence of failure to thrive and stunting, respectively. Results: Majority (70.6%) of the patients with malnutrition were from a low socioeconomic class. At baseline, failure to thrive and stunting were found among 17 (26.4%) cases and 11 (17.7%) controls, but the proportion reduced to six (9.7%) and three (4.8%), respectively, at the 13th week post adenotonsillectomy. There was a steady increase in weight-forage , height-forage , mid-upper arm circumference, and triceps skinfold thickness in both cases and controls from baseline to the 13th week. However, there was a significant difference in percentage variation of these variables between the two groups. Conclusions: Adenotonsillectomy improved the growth of children with obstructive adenotonsillar enlargement and hence recommended in cases with failure to thrive and stunting.